SolarWorld AG is a leader in recycling – Deutsche Solar GmbH, a subsidiary of the company, has been recycling silicon since 2001 and is now seen as a pioneer in the solar industry. The subsidiary specializes in adapting, refining and recovering silicon materials of various origins, including by-products of the semiconductor and PV panel manufacturing sectors or other industry sectors. The extensive machinery used for recycling also allows for the mechanical, chemical and thermal processing of different materials and offers a high level of flexibility and product variety. Deutsche Solar GmbH meets the DIN ISO 9001 and 14001 standards for the recycling of photovoltaic silicon, silicon wafers, silicon cells and solar panels.
Deutsche Solar GmbH offers a wide range of recycling services:
Smelting and thermal processing
Deutsche Solar uses the most advanced smelters to produce silicon blocks of up to 350 kilograms in addition to other alloys for non-solar applications. Other services include material purification, dopant production, material sampling, qualification of Si material properties, segregation cleaning and analysis and quality assurance tasks.
Mechanical processing of materials
Deutsche Solar uses the most advanced systems to mechanically process silicon. Tasks include cutting materials, sandblasting material surfaces and crushing and sorting silicon blocks.
- Diamond sawing
- Jaw crushing (customers can choose between low-contamination or low-abrasion crushing in the grain size range)
- Milling up to the µm range
- Sandblasting of cubic or planar materials on the metric ton scale
- Mechanical delayering of surfaces (glass, metal, wood, etc.)
Chemical processing of materials:
Deutsche Solar can chemically process materials of varying size and shape using fully and semi-automated etching systems. Surfaces are purified in either batch processes or continuously operated lines.
- Photovoltaics: Chemical processing and purification of silicon material surfaces throughout the photovoltaic value added chain
- PV and semiconductor industry: Cleaning of product carriers, selective etching of metals/metallic contaminations
- Other applications: Chemical delayering of glass, acid cleaning of metals
The testing laboratory of Deutsche Solar GmbH offers a wide range of analyses for photovoltaic and non-photovoltaic applications. These services can assist customers in the inspection of incoming and outgoing goods, for example. Analyses offered:
- Trace metal analysis of silicon using Glow Discharge Mass Spectrometry (GDMS)
- Verification of dopants in silicon
- Automated determination of conduction type
Material sorting and classification:
The recycling experts from Freiberg have extensive experience in the sorting and classification of materials, especially silicon. Contaminants with various properties can be removed from bulk materials to create usable material groups with high purity levels. The range of services include the following techniques:
- Classification according to customer-specific grain size class, dust removal from bulk materials
- Density-dependent separation of material mixes, mostly through visual inspection
- Separation of materials that have different conductivities
- Characterization of the resistivity and conductive properties of semiconductor materials
Target processing and manufacturing
Deutsche Solar has years of experience in sputtering silicon and producing multi-crystalline planar silicon targets in various geometries and sizes. The targets can be produced in various resistivity ranges by request. Used targets are recycled for optimal resource use and then used to produce new targets.